A printing device is a peripheral device of a computer. Generally, the printing device is in communication with the computer. By operating the computer, a document electronic file stored in the computer may be printed on a paper through the printing device. Consequently, a paper document corresponding to document electronic file may be generated by the printing device. For example, the document electronic file is a text file or an image file. Moreover, an inkjet printing device is a printing device that uses ink as the printing material.
FIG. 1 is a schematic perspective view illustrating the outward appearance of a conventional inkjet printing device. As shown in FIG. 1, the conventional inkjet printing device 1 comprises a print head 10, a first ink cartridge 11, a second ink cartridge 12, a transmission mechanism 13, a paper input tray 14, and a paper output tray 15. The first ink cartridge 11 is used for storing a first ink (not shown). The second ink cartridge 12 is located beside the first ink cartridge 11 and used for storing a second ink (not shown). For example, the first ink is a black ink, and the second ink is a color ink. The print head 10 comprises a first ink chamber 101, a first nozzle (not shown), a second chamber 102, and a second nozzle (not shown). The first ink chamber 101 is connected with the first ink cartridge 11 for storing the first ink which is transferred from the first ink cartridge 11. The second chamber 102 is connected with the second ink cartridge 12 for storing the second ink which is transferred from the second ink cartridge 12. The first nozzle is connected with the first ink chamber 101. The first ink stored within the first ink chamber 101 may be ejected through the first nozzle. The second nozzle is connected with the second chamber 102. The second ink stored within the second chamber 102 may be ejected through the second nozzle. The transmission mechanism 13 is connected with the print head 10. The transmission mechanism 13 is driven to move the print head 10, so that the first ink or the second ink may be ejected out and printed on any position of a blank paper P in an inkjet printing manner. The paper input tray 14 is used for placing the blank paper P thereon. After an inkjet printing task is performed, the paper P is exited to the paper output tray 15.
During the inkjet printing task of the conventional inkjet printing device 1 is performed, the blank paper P on the paper input tray 14 is fed into the inkjet printing device 1 in a feeding direction Y by a feeding mechanism (not shown), and the print head 10 is moved in a printing direction X by the transmission mechanism 13. The printing direction X is perpendicular to the feeding direction Y. After the inkjet printing task is completed, the paper P is exited to the paper output tray 15. The structures of the conventional inkjet printing device 1 and the printing process of the conventional inkjet printing device 1 have been mentioned above. However, if the inkjet printing task is repeatedly performed by the conventional inkjet printing device 1, two problems may occur. As for the first problem, the first nozzle and the second nozzle of the print head 10 are possibly clogged. In a case that the first nozzle and the second nozzle are clogged by dust, foreign matter or bubbles, the print head 10 fails to eject ink. Secondly, the first ink chamber 101 and the second chamber 102 are sealed structures and unable to be opened. Consequently, in a case that the first ink within the first ink chamber 101 and the second ink within the second ink chamber 102 are used up, the first ink chamber 101 and the second chamber 102 fail to be opened to be replenished with the first ink and the second ink. The second problem is to realize how to transfer the first ink within the first ink cartridge 11 and the second ink within the second ink cartridge 12 to the first ink chamber 101 and the second chamber 102.
For solving the above two problems, the inkjet printing device is usually equipped with a nozzle cleaning mechanism for preventing from occurrence of the clogged conditions of the nozzles. Hereinafter, the structures of a nozzle cleaning mechanism of a conventional inkjet printing device will be illustrated with reference to FIG. 2. FIG. 2 is a schematic perspective view illustrating a nozzle cleaning mechanism of a conventional inkjet printing device. The nozzle cleaning mechanism 16 is disposed within the conventional inkjet printing device 1 for eliminating the clogged conditions of the first nozzle and the second nozzle. As shown in FIG. 2, the nozzle cleaning mechanism 16 comprises a power pump 161, a connecting cover 162, a first duct 163, a second duct 164, a first discharge pipe 165, a second discharge pipe 166, and a storage element 167. The connecting cover 162 is connected with a first end 1631 of the first duct 163 and a first end 1641 of the second duct 164. The connecting cover 162 may be moved to a position to be contacted with the print head 10, so that the first nozzle and second nozzle are covered by the connecting cover 162. The power pump 161 is connected with a second end 1632 of the first duct 163 and a second end 1642 of the second duct 164. The power pump 161 may be driven to generate a suction force. In response to the suction force, the first ink within the first ink cartridge 11 and the second ink within the second ink cartridge 12 are sucked by the power pump 161. A first end 1651 of the first discharge pipe 165 is connected with the power pump 161. The first discharge pipe 165 is used for discharging the first ink that is sucked by the power pump 161. A first end 1661 of the second discharge pipe 166 is also connected with the power pump 161. The second discharge pipe 166 is used for discharging the second ink that is sucked by the power pump 161. The storage element 167 is connected with a second end 1652 of the first discharge pipe 165 and a second end 1662 of the second discharge pipe 166. The storage element 167 is used for storing the sucked first ink and the sucked second ink. For example, the storage element 167 is a waste ink box.
If the user finds that the first nozzle of the print head 10 has been clogged, the nozzle cleaning mechanism 16 may be enabled to have the connecting cover 162 move to a position under the print head 10 and cover the first nozzle and second nozzle. After the connecting cover 162 is coupled with the print head 10, the power pump 161 may be driven to generate a suction force. In response to the suction force, the first ink within the first ink chamber 101 is sucked by the power pump 161 and transferred through the first nozzle. At the time when the first ink is transferred through the first nozzle, the dust, foreign matter or bubbles within the first nozzle is flushed out of the first nozzle by the first ink, and thus the clogged condition of the first nozzle is minimized or eliminated. Then, the sucked first ink is sequentially transferred through the first duct 163, the power pump 161 and the first discharge pipe 165, and delivered to the storage element 167 for storage. Meanwhile, the nozzle cleaning task of the print head 10 is completed. Then, the connecting cover 162 is separated from the print head 10, and the conventional inkjet printing device 1 is in a ready-to-print status. The way of eliminating the clogged condition of the second nozzle is similar to the way of eliminating the clogged condition of the first nozzle, and is not redundantly described herein. As a consequence, the first problem of causing the clogged nozzle is solved.
Moreover, the use of the nozzle cleaning mechanism 16 is also capable of solving the second problem of realizing how to transfer the first ink and the second ink to the first ink chamber 101 and the second chamber 102. For refilling the first ink from the first ink cartridge 11 to the first ink chamber 101, the nozzle cleaning mechanism 16 may be enabled to have the connecting cover 162 move to a position under the print head 10 and cover the first nozzle and second nozzle. After the connecting cover 162 is coupled with the print head 10, the power pump 161 may be driven to generate a suction force. In response to the suction force, the air within the first ink chamber 101 is transferred through the first nozzle and ejected out. In addition, the air is sequentially transferred through the first duct 163 and the power pump 161, and then ejected out of the inkjet printing device 1. Meanwhile, no air is contained in the first ink chamber 101. Since the first ink chamber 101 is connected with the first ink cartridge 11, in response to the change of the pressure within the first ink chamber 101, the first ink within first ink cartridge 11 is transferred from the first ink cartridge 11 to the first ink chamber 101 in order to refill ink. As a consequence, the second problem of refilling ink is solved.
Although the use of the nozzle cleaning mechanism is effective to eliminate the clogged conditions of the first nozzle and the second nozzle, there are still some drawbacks. For example, if the first ink within the first ink chamber 101 and the second ink within the second ink chamber 102 contain bubbles, the presence of the bubbles may cause non-uniform distribution of the first ink and the second ink. Under this circumstance, the printing quality is deteriorated. As known, the conventional nozzle cleaning mechanism is unable to effectively remove the bubbles from the first ink and the second ink. Therefore, there is a need of providing an inkjet printing device capable of removing the bubbles from the ink.